Very expensive for the time, Queen Isabella "invested" the equivalent of $14,000 to finance Christopher Columbus's first expedition in search of the Indies. Although Columbus came nowhere near the United States, through the Columbian Exposition in Chicago, this series of stamps was the first to celebrate his landing on San Salvador. Columbus was helped by four influential members of the Spanish royal court: Fr. Diego de Deza of Salamanca (later Archbishop of Seville); Juan Cabrero, royal chamberlain; Luis de Santangel, King Ferdinand's keeper of the privy purse; and Raphael Sanchez, royal treasurer. Cabrero received Columbus's first letter announcing his discovery of a new world.